Independent suture tensioning and snaring apparatus

ABSTRACT

In repairing soft tissue with a bone anchoring instrument (such as reattaching a tendon of a torn rotator cuff), the bone anchoring instrument may be used to anchor the soft tissue to a region of bone. The anchors inserted into the underlying bone may have one or more lengths of suture or wire attached thereto which may be tensioned independently of one another to affix the soft tissue to the bone by having a selector mechanism selectively engage and disengage ratcheted tensioning wheels from one another. Suture loading mechanisms may be employed for passing suture lengths into and/or through the anchors prior to deployment into the bone where such mechanisms may employ suture snares which are configured to reconfigure from an expanded shape through which suture lengths may be easily passed to a low-profile shape which secures the suture lengths within the snare.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional U.S patent application Ser. No.14/449,723 filed Aug. 1, 2014, which claims the benefit of U.S patentapplication Ser. No. 12/487,352 filed Jun. 18, 2009, U.S. Pat. No.8,834,495 issued Sep. 16, 2014, which claims the benefit of U.S.Provisional Application No. 61/076,795 filed Jun. 30, 2008 and entitled“Independent Suture Tensioning and Snaring Apparatus”, the entirety ofwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to apparatus and methods for anchoringsoft tissue to bone. More particularly, the present invention relates toapparatus and methods for anchoring soft tissue to bone and selectivelysnaring, threading, and tensioning varying suture lengths from one ormore bone anchors independently of one another through a singleinstrument.

BACKGROUND OF THE INVENTION

Prior to the development of knotless designs, bone anchor deploymentinstruments typically utilized anchors which had suture material eitherpreloaded or incorporated eyelets through which a length of suture maybe loaded prior to anchor introduction into the bone. The sequence ofoperation for deploying the anchors generally entailed passing one ormore suture lengths through the soft tissue to be secured and thenapproximating the soft tissue to the underlying bone by tying one ormore knots.

Even with the advent of knotless bone anchor designs, the ability toaccurately and reliably apply tension to the sutures to approximate softtissues to bone created additional problems. Because of the nature ofknotless anchor designs, sutures are typically placed through the softtissue to be secured before coupling them with the anchor. This requiredthe inclusion of additional mechanisms for threading the anchors andtensioning the sutures.

Developments in constructs for approximating and securing soft tissue tobone, notably in the area of rotator cuff repair, have created the needto be able to independently secure, thread, and tension one or more ofthe suture strands passing through one or more bone anchors. This istypically apparent in the formation of crossed suture configurations,e.g., criss-cross type constructs, where suture limbs from two differentmedially placed anchors are loaded into a laterally placed anchor.Because the suture limbs may originate from different orientations orbone anchors, they may not have the same lengths and may thus need to betensioned independently of one another.

Additionally, in certain of the bone anchor insertion instrumentconfigurations described above, there exists a need to secure suturelimbs after they have been loaded into a threading or snaring device toprevent the separate suture limbs from dropping out of the insertiondevice. As the sutures are withdrawn over a distance through the anchorand into the inserter, the potential for the sutures pulling out of thesnare and the insertion device is significant.

Accordingly, devices and methods which allow for the tensioning ofseparate suture lengths independently of one another are desired. Inparticular, mechanisms to individually capture suture lengths and conveythem to tensioning mechanisms, e.g., ratchet wheels, which arecontrollable to enable a user to selectively tension either or bothindividual suture lengths are desired. Further, a suture threading andsnaring device that allows for single step loading and securing ofindependent suture limbs into knotless bone anchors is also desired. Inparticular, mechanisms that allow for the individual snaring andsecuring of suture limbs in conjunction with the use of a bone anchorinsertion device with independent tensioning mechanisms, and that conveythe independent suture limbs to the separate tensioning mechanisms,e.g., ratchet wheels, are also needed

SUMMARY OF THE INVENTION

In repairing soft tissue with a bone anchoring instrument (such asreattaching a tendon of a torn rotator cuff), the bone anchoringinstrument may be used to anchor the soft tissue to a region of bone.This may be accomplished generally by inserting at least one anchor intounderlying bone, locking the anchor into the bone, and subsequentlytensioning one or more lengths of suture or wire between the anchor toaffix the soft tissue. The lengths of suture or wire may be tensionedindependently of one another and subsequently immobilized or secured andthe anchoring instrument may be disassociated from the anchors leavingthem behind in the bone.

The suture tensioning mechanism may incorporate one or more rotatablewheels which are ratcheted to turn in a stepped or controlled manner ina first direction unless released by a ratchet release mechanism toallow for the ratcheted wheels to turn in a second opposite direction.One or more knobs may be rotatably attached to the one or more ratchetedwheels to provide a control handle for the user. Once the bone anchorhas been deployed, the user may turn the one or more knobs in the firstdirection to tension the suture about the ratcheted wheel and thusapproximate the soft tissue to the underlying bone.

Respective first and second knobs may extend from the instrument housingwhile coupled to respective first and second ratchet wheels which arerotatably positioned within the housing. First and second ratchet wheelsmay include respective ratcheting teeth such that rotation of the firstand second knobs by the user may in turn rotate ratchet wheels in afirst direction while rotation in a second opposite direction isinhibited. One or both respective ratchet releases may be depressed oractuated by the user to release the ratcheting mechanism and thus allowfor free rotation of the ratchet wheels in either the first or seconddirection. In this manner, one or both ratchet wheels may be releasedindependently of one another to facilitate individual tensioning of oneor both suture lengths via the ratchet wheels. Alternatively, bothratchet wheels may be simultaneously released by the simultaneousactuation of both ratchet releases.

In an exemplary use, when a first and second length of suture extendingfrom their respective bone anchors deployed within the underlying boneare initially tensioned, the selector may be placed in a neutralposition such that both first and second ratchet wheels are engaged bythe selector and both wheels are simultaneously rotatable. Rotation ofboth first and second ratchet wheels may accordingly tension bothlengths of suture simultaneously about their respective suture tracksfor initially eliminating any slack from the suture lengths.

To disengage the first and second ratchet wheels from one another, theselector may be actuated, e.g., by depressing the selector in a firstdirection, to slide into a first position. In this first position, thesecond ratchet wheel may be disengaged and the first ratchet wheel maybe engaged such that rotation of the knobs may in turn rotate only thefirst ratchet wheel to tension the first length of suture thereabout.With the second ratchet wheel disengaged from the knobs, the secondratchet wheel may remain stationary to maintain a constant tension levelupon its suture length while the first ratchet wheel may be rotated tofurther tension or loosen its first length of suture as appropriate.Similarly, the selector may be actuated to be re-positioned into asecond position where the first ratchet wheel is disengaged from theknobs and the second ratchet wheel is then engaged by the knobs torotate for tensioning or loosening its respective suture length. Suchindividual tensioning of the sutures may provide for fine tuning andoptimization of the soft tissue securement to the underlying bone.

As the selector is moved between positions during a procedure, aretaining member located along the selector shaft may slide over aninterface between the ratchet wheels to an provide an indication, suchas slight resistance or an audible click, to the user as to the relativemovement and positioning of the selector relative to the ratchet wheels.

Prior to tensioning the lengths of suture, a suture loader comprising asnaring and securing mechanism is provided to assist in conveying theseparate suture limbs to a respective independent tensioning ratchetwheel. The snaring mechanism includes at least two snares preloaded intothe suture loader. The securing mechanism includes a suture guidedisposed on the inserter. The suture guide manages and effectivelyroutes each snare and corresponding length of suture limbs from aninitial snaring position to a subsequent pre-tensioning position whereeach length of suture limb is drawn through the bone anchor prior to thetensioning process. The securing mechanism further includes at least twotraps and related shutters that may be movable either pivotably orslidably and operable to capture suture limbs disposed in acorresponding snare in the initial snaring position within the traps andprior to the suture limbs being withdrawn through a bone anchor by thetensioning mechanism. The suture limbs are engaged by at least two snareend portions that each comprise a plurality of teeth for engaging,compressing into, or biting into the end portions of the respectivesuture limbs.

Thus, the disclosed embodiments comprise a combination of features andcharacteristics which are directed to allow it to overcome variousshortcomings of prior devices. The various characteristics describedabove, as well as other features, will be readily apparent to thoseskilled in the art upon reading the following detailed description ofthe preferred embodiments of the invention, and by referring to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a representative bone anchoringinstrument.

FIG. 2 illustrates another perspective view of an a representative boneanchoring assembly which shows the deployable bone anchors which may beloaded within the instrument.

FIG. 3 illustrates a perspective view of an additional bone anchoringinstrument.

FIG. 4 illustrates a perspective view of one example of a suturetensioning assembly configured to simultaneously tension two separatesuture lengths.

FIGS. 5A and 5B illustrate perspective views of the suture tensionassembly alternately configured to selectively tension a first or asecond suture length.

FIG. 6 illustrates a perspective view of an exploded tensioning assemblyshowing the separate tensioning mechanisms and a selector assembly forselectively engaging one or both tensioning mechanisms.

FIG. 7A illustrates a cross-sectional end view of the selector assemblyin a first position to engage both a first and a second tensioningmechanism to simultaneously tension a first and a second suture length,respectively.

FIG. 7B illustrates the cross-sectional end view of FIG. 6A where theselector assembly is repositioned in a second position to engage asingle tensioning mechanism for tensioning a single suture length.

FIGS. 8A and 8B illustrate cross-sectional end views of anothervariation of a selector assembly which is configured to selectivelyengage one or both the tensioning mechanisms in preset positions.

FIGS. 9A and 9B illustrate perspective and detail perspective views,respectively, of an exemplary bone anchor insertion device positionedwithin a suture loader mechanism.

FIGS. 10A, 10B, and 10C illustrate perspective views of an embodiment ofthe removable suture loader disposed at a distal end of a bone anchoringinstrument.

FIGS. 11A and 11B illustrate side views of a suture loader mechanism.

FIGS. 11C and 11D illustrate perspective views of an embodiment of asuture loader mechanism.

FIGS. 12A and 12B illustrate a perspective view of an embodiment of thesuture snaring end portion.

FIGS. 13 and 14 illustrate a perspective view of an additionalembodiment of the suture snaring end portion.

DETAILED DESCRIPTION OF THE INVENTION

The independent suture tensioning mechanisms described herein may beutilized with any number of bone anchors as well as related insertionand deployment instruments. In repairing soft tissue with a boneanchoring instrument (such as reattaching a tendon of a torn rotatorcuff), the bone anchoring instrument may be used to anchor the softtissue to a region of bone. This may be accomplished generally byinserting at least one anchor into the underlying bone, locking theanchor into the bone, and subsequently tensioning one or more lengths ofsuture or wire stitched in the soft tissue between the anchor to affixthe soft tissue. The lengths of suture or wire may be tensionedindependently of one another and subsequently immobilized or secured andthe anchoring instrument may be disassociated from the anchor leaving itbehind in the bone. Such an anchoring instrument may eliminate the needto separately pass suture or wire or tying knots thus allowing theprocedure to be performed without the need to move an arthroscope froman articular side to a bursal side of the cuff. Moreover, the relativelysmall diameter of the bone anchor allows for a reduced entry holethrough the cuff during delivery and deployment.

Some examples of illustrative bone anchoring devices which mayincorporate such suture tensioning mechanisms are shown and described indetail in U.S. Pat. 6,780,198 and U.S. Pat. App. 2005/033364 A1, each ofwhich is incorporated herein by reference. Generally, such bone anchordeployment instruments may incorporate one or more ratcheted tensioningmechanisms, such as a rotatable wheel, around which a length of sutureto be deployed and tensioned is at least partially wrapped or retained.Once the anchor has been deployed into the bone and the suture extendingfrom the anchor is to be tensioned, the tensioning mechanism may berotated in a first direction (as in the wheel configuration) to wind theslack suture about the mechanism and thereby apply tension to the sutureends, e.g., to approximate and/or secure soft tissue to the bone.

One embodiment of a bone anchoring insertion instrument having aratcheted tensioning mechanism configured as a rotatable wheel is shownin the perspective view of FIG. 1. As previously mentioned, furtherdetails are disclosed in U.S. Pat. 6,780,198 and U.S. Pat. App.2005/033364 A1 incorporated hereinabove. A bone anchoring insertioninstrument 10 may incorporate an inserter handle 11 and an outer tube 12extending distally from handle portion 11. The handle portion 11 maycomprise a housing 13 which is shaped and configured to accommodatecomponents for effecting the insertion of one or more bone anchors forany number of orthopedic procedures such as repair of a rotator cuffwhere a portion of soft tissue is reattached to an adjacent bone. A handlever 16 may be pivotally attached to housing 13.

The suture tensioning mechanism may incorporate a rotatable wheel 15which is ratcheted to turn in a stepped or controlled manner in a firstdirection unless released by a ratchet release mechanism to allow forthe ratcheted wheel 15 to turn in a second opposite direction. One ormore knobs 14 may be rotatably attached to the one or more ratchetedwheels 15 to provide a control handle for the user. The bone anchor maybe deployed by actuating the pivotable hand lever 16 downwardly. Oncethe bone anchor has been deployed, the user may turn the one or moreknobs 14 in the first direction to tension the suture about theratcheted wheel 15 and thus approximate the soft tissue to theunderlying bone.

The outer tube 12 projecting distally from handle 11 may define alongitudinal slot or opening 19 as well as a suture opening 17 formed inits distal end. A separate inner slotted tube 18 may also be disposedcoaxially within the outer tube 12 such that inner tube 18 is fixedrelative to the outer tube 12 to prevent relative sliding or rotationalmovement between the two. In this manner, inner tube 18 may function asa mandrel or stop for the bone anchors during an insertion procedure.

As illustrated in the perspective view of FIG. 2, a separate pull tube20 may also be inserted in a coaxial relationship into the distal end ofthe inner slotted tube 18. A portion of the distal end of the pull tube20 may be constructed such that part of the cylindrical sidewall is cutaway to form a semi-cylindrical shape which forms a suture opening 22.In this manner, one or more bone anchors 24 to which a length of sutureis attached may be affixed to the distal end of pull tube 20 fordelivery and deployment into the bone.

Referring now to FIG. 3, another embodiment of a bone anchoringinsertion instrument is shown. Bone anchor insertion device 30 iscomprised of handle 32, outer tube 34, and trigger 36. Suture knob 38 isdisposed on handle 32, and is rotatably attached to a ratcheted wheel(not shown). Bone anchor 31 is disposed at a distal end of outer tube 34and is threaded with a length of suture (not shown) which is alsoretained on the ratcheted wheel. The bone anchor 31 is inserted into abone hole and the length of suture is tensioned by rotating suture knob38. After the length of suture is tensioned to a desired degree, trigger36 is actuated in order to deploy and lock the bone anchor 31 within thebone hole.

The bone anchoring insertion instruments shown above are described asexemplary devices which may incorporate a suture tensioning mechanismconfigured to tension different suture lengths simultaneously orindependently of one another and are not intended to be limiting. Nowturning to an example of such a suture tensioning mechanism, FIG. 4illustrates a perspective view of a suture tensioning mechanism 40housed within handle housing 41. In this variation, respective first andsecond knobs 42 a, 42 b may extend from housing 41 while coupled torespective first and second ratchet wheels 44 a, 44 b which arerotatably positioned within housing 41. First and second ratchet wheels44 a, 44 b may include respective ratcheting teeth 50 a, 50 b such thatrotation of the first and second knobs 42 a, 42 b by the user may inturn rotate ratchet wheels 44 a, 44 b in a first direction whilerotation in a second opposite direction is inhibited.

One or both respective ratchet releases 46 a, 46 b may be depressed oractuated by the user to release the ratcheting mechanism and thus allowfor free rotation of ratchet wheels 44 a, 44 b in either the first orsecond direction. For instance, actuation of first ratchet release 46 amay release the ratcheting mechanism from ratcheting teeth 50 a andactuation of second ratchet release 46 b may release the ratchetingmechanism from ratcheting teeth 50 b. In this manner, one or bothratchet wheels 44 a, 44 b may be released independently of one anotherto facilitate individual tensioning of one or both suture lengths viaratchet wheels 44 a, 44 b, as further described below. Alternatively,both ratchet wheels 44 a, 44 b may be simultaneously released by thesimultaneous actuation of both ratchet releases 46 a, 46 b. Furthermoreas shown, first and second ratchet wheels 44 a, 44 b may each define agroove or track 52 a, 52 b about its circumference within whichrespective lengths of suture to be tensioned may be at least partiallywrapped about.

In an exemplary use, when a first and second length of suture extendingfrom their respective bone anchors deployed within the underlying boneare initially tensioned, selector 48 may be placed in a neutralposition, as shown in FIG. 4, such that both first and second ratchetwheels 44 a, 44 b are engaged by selector 48 and both wheels aresimultaneously rotatable by first and second knobs 42 a, 42 b. Rotationof both first and second ratchet wheels 44 a, 44 b may accordinglytension both lengths of suture simultaneously about their respectivesuture tracks 52 a, 52 b for initially eliminating any slack from thesuture lengths.

To disengage first and second ratchet wheels 44 a, 44 b from oneanother, selector 48 may be actuated, e.g., by depressing selector 48 ina first direction, to slide into a first position 48′, as illustrated inthe perspective view of FIG. 5A. In this first position 48′, secondratchet wheel 44 b may be disengaged and first ratchet wheel 44 a may beengaged such that rotation of knobs 42 a, 42 b may in turn rotate onlyfirst ratchet wheel 44 a to tension the first length of suturethereabout. With second ratchet wheel 44 b disengaged from knobs 42 a,42 b, second ratchet wheel 44 b may remain stationary to maintain aconstant tension level upon its suture length while first ratchet wheel44 a may be rotated to further tension or loosen its first length ofsuture as appropriate.

Similarly, selector 48 may be actuated to be re-positioned into a secondposition 48″, as illustrated in the perspective view of FIG. 5B, wherefirst ratchet wheel 44 a is disengaged from knobs 42 a, 42 b and secondratchet wheel 44 b is then engaged by the knobs to rotate for tensioningor loosening its respective suture length. Alternatively, engagement ofselector 48 into its first position 48′ may allow for rotation of firstratchet wheel 44 a by only first knob 42 a and likewise engagement ofselector 48 into its second position 48″ may allow for rotation ofsecond ratchet wheel 44 b by only second knob 42 b. Selector 48 may berepositioned in its neutral position or its first or second position atany time during a procedure thus allowing for simultaneous tensioning orselective tensioning of its first or second suture lengths as necessary.Such individual tensioning of the sutures may provide for fine tuningand optimization of the soft tissue securement to the underlying bone.

As illustrated in the perspective view of the exploded tensioningmechanism assembly in FIG. 6, selector 48 may comprise in one variationa shaft 54 translatable along its axial length and positioned throughratchet wheels 44 a, 44 b. An engagement member having first and secondengaging portions 60 a, 60 b may be positioned along the shaft 54, e.g.,along a central portion of shaft 54. The engaging portions 60 a, 60 bmay comprise a separate or integrated portion of shaft 54 which has asecond diameter larger than a first diameter of the shaft 54 with one ormore teeth or projections defined along the engaging portions 60 a, 60 band extending in a longitudinal direction. The engaging portions 60 a,60 b may further include a receiving groove 62 circumferentially definedbetween engaging portions 60 a, 60 b such that receiving groove 62 issized to receive a retaining member 64, e.g., C-clip or O-ring, whichmay be secured within receiving groove 62. Once retaining member 64 issecured within receiving groove 62, an outer diameter of the member 64may extend just beyond the second diameter of engaging portions 60 a, 60b.

First and second ratchet wheels 44 a, 44 b may each define a respectivereceiving recess 66 a, 66 b molded or otherwise formed annularly aboutthe opening through which selector shaft 54 passes such that the annularcavities are in apposition to one another. Receiving recess 66 a, 66 bmay each form an opening along the surfaces of ratchet wheels 44 a, 44 bsuch that when the wheels are positioned adjacent to one another whenassembled, receiving recess 66 a, 66 b forms an enclosed cavity withinwhich first and second engaging portions 60 a, 60 b are translatablyslidable.

As illustrated in the cross-sectional end view of FIG. 7A, the assembledratchet wheels 44 a, 44 b are shown positioned adjacent to one anothersuch that the receiving recess 66 a, 66 b forms the enclosed cavity. Theinterior surface of receiving recess 66 a, 66 b may each define one ormore engaging teeth or projections 70 a, 70 b which extendlongitudinally therethrough such that the engaging teeth or projectionsdefined along engaging portions 60 a, 60 b are received in acomplementary manner where the engaging portions 60 a, 60 b becomesrotationally coupled to one or both ratchet wheels 44 a, 44 b viaengagement with the interior of receiving recess 66 a, 66 b. Because ofthe longitudinal direction which the engaging teeth along engagingportions 60 a, 60 b and the engaging teeth 70 a, 70 b along the interiorsurface of receiving recess 66 a, 66 b are positioned, selector 48 mayremain slidingly translatable along its longitudinal axis, as indicatedby the arrow, to translate freely within receiving recess 66 a, 66 bwhile remaining in rotational engagement with one or both ratchet wheels44 a, 44 b.

When selector 48 is positioned in its neutral position as describedabove, first and second engaging portions 60 a, 60 b may be engaged toboth first and second ratchet wheels 44 a, 44 b, as shown, to allow forsimultaneous rotation of the wheels and tensioning of their respectivesuture lengths. However, upon actuation of selector 48 to its firstposition, as shown in the cross-sectional end view of FIG. 7B, selector48 and engaging portions 60 a, 60 b may slide within receiving recess 66a, 66 b such that second engaging portion 60 b becomes disengaged fromthe teeth or projections along second receiving recess 66 b and becomesengaged solely with first ratchet wheel 44 a. In this manner, firstratchet wheel 44 a may be actuated to selectively tension just the firstlength of suture. Actuating selector 48 to slide into its secondposition may likewise disengage first and second engaging portions 60 a,60 b from first ratchet wheel 44 a such that second ratchet wheel 44 bbecomes solely engaged for tensioning just the second length of suture.Selector 48 may be accordingly engaged and disengaged freely from eitherratchet wheel to selectively tension one or both lengths of suturesduring a procedure.

To facilitate the selective engagement of one or both ratchet wheels 44a, 44 b, the exterior circumferential surface of retaining member 64 mayremain in sliding contact 72 with the interior surface of receivingrecess 66 a, 66 b to provide tactile feedback to the user. As selector48 is moved between positions during a procedure, the retaining member64 may slide over the interface between the ratchet wheels 44 a, 44 band provide an indication, such as slight resistance or an audibleclick, to the user as to the relative movement and positioning ofselector 48 relative to the ratchet wheels 44 a, 44 b.

In yet another variation, FIGS. 8A and 8B illustrate cross-sectional endviews of a selector 80 mechanism which is configured to toggle betweenone of two positions. In the end view of FIG. 8A, selector 80 may betoggled in a first position where engaging portion 82 located along theselector shaft is engaged to both first and second ratchet wheels 44 a,44 b such that both wheels are coupled and actuation of knobs 42 a, 42 bsimultaneously tensions (or loosens) each respective suture length. Whenselector 80 is toggled into its second position, as illustrated in FIG.8B, ratchet wheels 44 a, 44 b may be uncoupled from one another to allowfor individual suture tensioning as described above. In this example, aportion of selector 80 may define a keyed length 84 such that selector80 is capable of being toggled in only one or two positions. Othervariations for limiting selector position may, of course, be utilizedwith the tensioning mechanisms described above.

Aside from independently tensioning suture lengths after one or morebone anchors have been deployed in the bone, additional mechanisms maybe optionally utilized to facilitate the passage and loading of multiplesuture lengths into or through the one or more bone anchors prior toanchor deployment. One embodiment is illustrated in the perspectiveassembly view of FIG. 9A which shows an exemplary bone anchor insertiondevice 30, as previously described, having a suture loader mechanism 90(described in further detail below) into which outer tube 91 having boneanchor 31 may be introduced. Additionally, in certain embodiments boneanchor insertion device 30 may comprise a suture tensioning mechanism 40according to the embodiments described herein. FIG. 9B shows a detailperspective view of suture loader 90 and outer tube 91 with bone anchor31 inserted within loader 90.

Generally, suture loader 90 may define a tube receiving channel 89 intowhich outer tube 91 may be slidably and removably positioned. With boneanchor 31 positioned distally of outer tube 91, one or more suturesnares 96 a, 96 b (also described in further detail below) may be passedthrough the anchor 31 and through suture traps 93 a, 93 b havingapertures 88 a, 88 b. Appropriate suture lengths may be passed throughthe one or more suture snares 96 a, 96 b which may be positioned withincorresponding apertures 88 a, 88 b of traps 93 a, 93 b defined throughloader 90. With the suture lengths positioned through apertures 98 a, 98b of snares 96 a, 96 b, they may be secured by snares 96 a, 96 b andpassed through anchor 31 via loader 90.

Now referring to FIGS. 10A to 10C, detail side views of suture loader 90are illustrated showing examples of snaring mechanism and securingmechanism. As aforementioned, the suture loader 90 mechanism may beutilized with any of the bone anchoring instruments described herein forfacilitating the loading of suture lengths through the one or more boneanchors and is not intended to be limiting. Suture loader 90 may beremovably disposed at a distal end of outer tube 91 of a bone anchoringinsertion instrument. Suture loader 90 may include suture guide 92disposed at a distal end of loader 90 and in proximity to a bone anchor31 disposed at the distal end of outer tube 91. Suture loader 90 mayalso include suture traps 93 a, 93 b and suture retaining members (orshutters) 94 a, 94 b. Traps 93 a, 93 b include apertures 88 a, 88 b (seeFIG. 9B) and are located proximally from guide 92 and radially spacedfrom outer tube 91 in proximity to suture trap shutters 94 a, 94 b.Shutters 94 a, 94 b are pivotable in a generally radial direction withrespect to outer tube 91 and may be configured to enclose traps 93 a, 93b or to provide for a radial opening for traps 93 a, 93 b. Shutters 94a, 94 b may be characterized by grooves 95 a, 95 b to help guidemovement of the shutters.

Suture snares 96 a, 96 b may be provided and are preloaded within outertube 91 and routed through the bone anchor 31 such that a free portionof snares 96 a, 96 b is exposed. A proximal portion of snares 96 a, 96 bmay be retained on the tensioning mechanism of the bone anchor insertiondevice 30. Snares 96 a, 96 b may include snare ends 97 a, 97 b. Snareends 97 a, 97 b may be characterized by apertures 98 a, 98 b and aplurality of teeth 99 located within apertures 98 a, 98 b. In apre-snaring configuration, snares 96 a, 96 b are directed out from thebone anchor 31 and inserted into guide 92. Snare ends 97 a, 97 b arepositioned within apertures 88 a, 88 b of traps 93 a, 93 b,respectively, and shutters 94 a, 94 b are positioned in an openconfiguration. Once a surgeon has placed a stitched loop of suture intoa portion of soft tissue desired to be affixed near a bone surface, theseparate free ends of suture, or suture limbs, may be respectivelythreaded into snare ends 97 a, 97 b and the shutters 94 a, 94 b may bepivoted to a closed configuration, thereby securing suture within snares96 a, 96 b. In this configuration, the separate free ends of suture andthe corresponding snare ends 97 a, 97 b are also secured with traps 93a, 93 b such that the free ends do not drop out of position both withinapertures 98 a, 98 b of snare ends 97 a, 97 b and with respect to theinsertion instrument itself.

With the free ends of the suture and snare ends 97 a, 97 b secured intraps 93 a, 93 b, snares 96 a, 96 b may be withdrawn through the boneanchor 31 and into outer tube 91 by actuating the tensioning mechanism.As snare ends 97 a, 97 b and the free ends of the suture are drawnthrough traps 93 a, 93 b and shutters 94 a, 94 b, apertures 98 a, 98 bare compressed between the outer walls of traps 93 a, 93 b such that theplurality of teeth 99 on both snare ends 97 a, 97 b are compressed orbite into the corresponding free ends of suture. With the free ends ofsuture retained within snare ends 97 a, 97 b, snares 96 a, 96 b aredrawn through suture loader 90 and into the bone anchor 31 and outertube 91. Specifically, as the tensioning mechanism is actuated, snares96 a, 96 b are routed through suture guide 92 and through the boneanchor and then into outer tube 91. Once snares 96 a, 96 b and the freeends of suture have been substantially withdrawn through the bone anchor31 and into outer tube 91 to create a pre-tensioning configuration,suture loader 90 may be removed from outer tube 91. The separate freeends of suture are thereby engaged by the tensioning mechanism of thebone anchoring insertion instrument and may be independently tensionedas desired and described above.

FIGS. 11A and 11B show respective side views of suture loader 90illustrating details such as the suture guide 92 passage disposeddistally from channel 89, as well as respective apertures 88 a, 88 b andcorresponding shutters 94 a, 94 b spaced radially from channel 89.Referring now to FIGS. 11C and 11D, in certain embodiments the sutureloader mechanism may be disposed at a more proximal location withrespect to outer tube 291 of a bone anchoring insertion instrument 200.In these embodiments, suture loader 290 may include suture guide 292,suture traps 293 a, 293 b and suture retaining members 294 a, 294 b.Traps 293 a, 293 b include apertures 288 a, 288 b and are locatedadjacent to handle 210 in proximity to retaining members 294 a, 294 b.Retaining members 294 a, 294 b are slidable in a generally axiallydirection with respect to outer tube 291 and may be configured toenclose traps 293 a, 293 b or alternatively to provide for an openingthrough traps 293 a, 293 b and access to apertures 298 a, 298 b. Suturesnares 296 a, 296 b may be provided and are preloaded within boneanchoring instrument 200 and routed through outer tube 291 and boneanchor 231 such that snare ends 297 a, 297 b are housed within suturetraps 293 a, 293 b, respectively. Snare ends 297 a, 297 b may becharacterized by snare apertures 298 a, 298 b and a plurality of teeth299 located within apertures 298 a, 298 b.

The separate free ends from a stitched loop of suture may berespectively threaded into snare ends 297 a, 297 b and suture retainingmembers 294 a, 294 b may be slid to a closed configuration, therebysecuring the suture free ends within snares 296 a, 296 b. Snares 296 a,296 b may then be withdrawn into outer tube 291 through guide 292 suchthat apertures 298 a, 298 b are compressed, thereby resulting in theplurality of teeth on snare ends 297 a, 297 b compressing or biting intothe corresponding free end of suture. With the free ends of suturesecured within snare ends 297 a, 297 b, snare ends 297 a, 297 b arepulled in a generally distal direction through outer tube 291 andthrough bone anchor 231 by actuation of the tensioning mechanism, wheresnare ends 297 a, 297 b and the corresponding free ends of suture arerouted through bone anchor 231 and then turned to be pulled back throughouter tube 291 in a generally proximal direction toward handle 210. Thefree ends of suture ultimately engage the tensioning mechanism of thebone anchoring instrument and may then be independently tensioned asdesired and as described above.

Referring now to FIGS. 12A and 12B, one embodiment of a snare end isshown. In certain embodiments, snare end 100 may include body 102 whichdefines a proximal loop 104 and which form arms 108 a, 108 b whichextend distally to form aperture 109 as a closed loop. One or both arms108 a, 108 b may further define suture securement members orprojections, e.g., a plurality of teeth 106, which extend towards oneanother in apposition along opposing arms 108 a, 108 b and which areconfigured to interdigitate or close upon one another when snare end 100is collapsed or urged into its low profile or closed configuration forsnaring or securing a suture length. In certain embodiments, a length ofmaterial such as a polyester strand may be threaded through loop 104 anddrawn through the bone anchor and attached to the tensioning mechanism.

Now referring to FIG. 12B, after a strand of suture 101 is threadedthrough aperture 109, which is positioned within aperture 98 a and/or 98b of suture loader 90 as described above, snare end 100 is compressedsuch that arms 108 a, 108 b are pushed toward one another, therebyclosing aperture 109 and causing the plurality of teeth 106 to engagethe strand of suture 101. In certain embodiments, the compression ofsnare end 100 takes place as snare end 100 is withdrawn through a sutureloader 90, as described above. The plurality of teeth 106 of suture end100 compress or bite into the strand of suture 101, resulting in aresistance to the strand of suture 101 pulling out of aperture 109 whenplaced under tensile load.

Referring now to FIGS. 13 and 14, an additional embodiment of a snareend is shown. Snare end 110 may include body 112, slit 114, andplurality of teeth 116. Arms 118 a, 118 b are formed on either side ofslit 114. In certain embodiments, body 112 is also part of a length ofmaterial included with the larger snare which is routed through the boneanchor and attached to the tensioning mechanism. Snare end 110 ispreferably fabricated from stainless steel by laser cutting, but may befabricated from many different materials (e.g., carbon steel orberyllium copper) and by various methods (e.g., photochemical etching,stamping or wire EDM). Referring now to FIG. 14, snare end 110 has beenconfigured to accept a strand of suture where arms 118 a, 118 b havebeen deflected to create aperture 120, which is capable of receiving astrand of suture. In this variation, arms 118 a, 118 b may be urged orformed to configure into an expanded profile by bending or curvingout-of-plane in opposing directions relative to a proximal end of body112. After a strand of suture is threaded through aperture 120, snareend 110 is reformed to the configuration shown in FIG. 13 such that thestrand of suture is captured by plurality of teeth 116 in a shearingtype action. In certain embodiments, the reformation of snare end 110takes place as snare end 110 is withdrawn through a suture loader, asdescribed above. The plurality of teeth 116 of suture end 110 compressor bite into the strand of suture, resulting in a resistance to thestrand of suture pulling out of aperture 120 when placed under tensileload.

Generally, the suture snares described herein may be utilized inconjunction with any of the suture loader embodiments described above.Alternatively, in certain embodiments the suture snares 100 or 110described above may be used independently of a suture loader. In theseembodiments, the suture snare is preferably drawn through the boneanchor disposed at the distal end of the bone anchoring instrument, suchthat the bone anchor compresses the suture snare with a free end ofsuture disposed therein thereby closing the aperture of the suture snareand causing the plurality of teeth to engage or bite into the free endof suture.

While preferred embodiments of this invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the scope or teaching herein. The embodimentsdescribed herein are exemplary only and are not limiting. Because manyvarying and different embodiments may be made within the scope of thepresent teachings, including equivalent structures or materialshereafter thought of, and because many modifications may be made in theembodiments herein detailed in accordance with the descriptiverequirements of the law, it is to be understood that the details hereinare to be interpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A method of loading a length of suture into abone anchor, comprising: passing a first suture length through a firstsuture snare positioned within a first aperture defined through ahousing; wherein the first suture snare comprises one or moreprojections positioned in apposition along the first suture snare;retaining the first suture snare and the first suture length within thefirst aperture; securing the first suture length to the first suturesnare; withdrawing the first suture snare through the housing whilepulling the first suture length therealong; and passing the first suturelength through at least one bone anchor while withdrawing the firstsuture snare; wherein during the step of passing the one or moreprojections are spaced away from the first aperture.
 2. The method ofclaim 1 further comprising: passing a second suture length through asecond suture snare positioned within a second aperture defined throughthe housing; retaining the second suture snare and the second suturelength within the second aperture; securing the second suture length tothe second suture snare; withdrawing the second suture snare through thehousing while pulling the second suture length therealong; and passingthe second suture length through the at least one bone anchor whilewithdrawing the second suture snare.
 3. The method of claim 1 whereinretaining the first suture snare and the first suture length furthercomprises moving a first retaining member from an open configurationwhere the first aperture is exposed to a closed configuration where thefirst aperture is covered.
 4. The method of claim 1 wherein securing thefirst suture length further comprises: compressing the first suturesnare such that the one or more projections are urged toward oneanother; and engaging the first suture length between the one or moreprojections.
 5. The method of claim 1 wherein securing the first suturelength further comprises: placing the first suture snare under a tensileload such that the one or more projections are urged toward one anotherin a shearing motion; and engaging the first suture length between theone or more projections.
 6. The method of claim 1 wherein withdrawingthe first suture snare comprises passing the first suture snare andfirst suture length through a guide section disposed in the housing, theguide section defining a first passage.
 7. The method of claim 1 whereinwithdrawing the first suture snare comprises actuating a suturetensioning mechanism positioned on a bone anchoring instrument, the boneanchoring instrument coupled to the bone anchor.
 8. The method of claim2 wherein the first and second suture snares are withdrawn substantiallysimultaneously.
 9. The method of claim 1 wherein the step of securingthe first suture length further comprises drawing the one or moreprojections through the first aperture so as to engage the one or moreprojections with the first suture length.
 10. The method of claim 1wherein the one or more projections comprise a plurality of teeth andwherein during the step of securing, the teeth bite into the firstsuture length.
 11. A method of loading a length of suture into a boneanchor, comprising: passing a first suture length through a first suturesnare positioned about a first aperture defined through a housing,wherein the first suture snare comprises one or more projectionspositioned in apposition along the first suture snare; retaining thefirst suture snare and the first suture length within the firstaperture; securing the first suture length to the first suture snare;withdrawing the first suture snare through the housing while pulling thefirst suture length therealong; and passing the first suture lengththrough at least one bone anchor while withdrawing the first suturesnare; wherein during the step of passing and retaining the one or moreprojections are recessed away from the first aperture.
 12. The method ofclaim 11 further comprising: passing a second suture length through asecond suture snare positioned within a second aperture defined throughthe housing, wherein the second suture snare comprises one or moreprojections positioned in apposition along the second suture snare;retaining the second suture snare and the second suture length withinthe second aperture; securing the second suture length to the secondsuture snare; withdrawing the second suture snare through the housingwhile pulling the second suture length therealong; and passing thesecond suture length through the at least one bone anchor whilewithdrawing the second suture snare wherein during the step of passingand retaining the one or more projections on the second suture snare arerecessed within the housing.
 13. The method of claim 11 whereinretaining the first suture snare and the first suture length furthercomprises moving a first retaining member from an open configurationwhere the first aperture is exposed to a closed configuration where thefirst aperture is covered.
 14. The method of claim 11 wherein securingthe first suture length further comprises: compressing the first suturesnare such that the one or more projections are urged toward oneanother; and engaging the first suture length between the one or moreprojections.
 15. The method of claim 11 wherein withdrawing the firstsuture snare comprises passing the first suture snare and first suturelength through a guide section disposed in the housing, the guidesection defining a first passage.
 16. The method of claim 11 whereinwithdrawing the first suture snare comprises actuating a suturetensioning mechanism positioned on a bone anchoring instrument.
 17. Themethod of claim 12 wherein the first and second suture snares arewithdrawn substantially simultaneously.
 18. The method of claim 11wherein the step of securing the first suture length further comprisesdrawing the one or more projections through the first aperture so thatthe one or more projections are no longer recessed so as to engage theone or more projections with the first suture length.
 19. The method ofclaim 11 wherein the one or more projections comprise a plurality ofteeth and wherein during the step of securing, the teeth bite into thefirst suture length.
 20. A method of loading a length of suture into abone anchor, comprising: passing a first suture length through a firstaperture defined through a housing, a first suture snare at leastpartially recessed within the housing and adjacent the first aperture,the first suture snare recessed so as to at least partially cover one ormore projections positioned in apposition along the first suture snare;retaining the first suture snare and the first suture length within thefirst aperture; securing the first suture length to the first suturesnare; withdrawing the first suture snare through the housing whilepulling the first suture length therealong; and passing the first suturelength through at least one bone anchor while withdrawing the firstsuture snare.